Composite ski boot

ABSTRACT

A boot, preferably for skiing and other sports activities, designed for performance as well as comfort. The preferred embodiment of the boot includes rigid upper and lower frames with a conformable cuff and shell. The boot is open in front to allow an inner flexible boot to be easily inserted as well as removed. A controlled flex unit controls the movement of the upper frame relative to the lower frame while maintaining the lateral stability of the boot.

RELATED APPLICATIONS

[0001] This application is a continuation-in-part of Ser. No. 09/535,670 that is a continuation-in-part of Ser. No. 09/170,344 and relates to provisional application No. 60/241,193 and provisional application No. 60/272,882.

FIELD OF THE INVENTION

[0002] This application relates to the field of boots and other footwear and particularly to ski and snowboarding boots.

BACKGROUND OF THE INVENTION

[0003] Ski boots are a critical component in enhancing skier performance. Typically, ski boots have sacrificed comfort for performance or performance for comfort. Most alpine ski boots include a rigid plastic body with an inner lining. The entire body is normally formed of a single stiff material. In order to achieve performance, the rigid plastic body includes a rigid lower shell and sole for attachment to the bindings of the ski, a rigid upper cuff to allow force to be applied to the ski in order to drive the ski during turns, a pivot or flexion element to allow the upper cuff to pivot relative to the lower shell, and an inner lining.

[0004] These elements combine to create a ski boot that is relatively heavy, extremely stiff compared to everyday walking boots or shoes, and awkward to walk in. Additionally, these boots are difficult to put on and take off as well as to adjust for proper fit. The stiff material used for the body does not conform to the shape of the user's calves, shins, ankles and feet. Thus, the user's legs and feet are constricted by the boots creating a tendency to restrict blood flow to the skier's feet causing discomfort and increased susceptibility to the cold. The boots are also extremely difficult to maneuver about in when not attached to skis. They are heavy, cumbersome and slippery on most surfaces. They create a liability in parking lots and ski lodges.

[0005] These prior boots have also been relatively expensive. Previous boots have not been adjustable to different sizes of feet, thus manufacturers must produce and stock components for every size of skier feet.

[0006] A number of prior ski boots have attempted to solve this problem by providing a ski boot that incorporates a flexible inner boot that is inserted into a rigid boot brace. This type of boot is disclosed in U.S. Pat. Nos. 4,959,912; 5,068,984; and 5,142,798, all issued to Kaufman et al. However, the boots disclosed in these patents are not able to conform to the shape of the skier's shins, calves and feet. The shin pieces and forefoot pieces are formed of rigid materials and are not able to conform to the skier. Further, these boots do not disclose using a controlled flex unit to allow the boot to be progressively flexed nor do the boots allow the canting and the flex of the boot to be adjusted.

[0007] Another type of this boot design is disclosed in U.S. Pat. No. 5,992,872, issued to Proctor. The boot disclosed in this patent also uses a rigid ankle cuff and does not provide a controlled flex unit or adjustability of the flex and canting of the boot. Similarly, U.S. Pat. No. 6,021,589, issued to Cagliari et al. discloses a ski boot using a brace and soft inner boot. The brace is formed of a single material, thus it can be either rigid or able to conform to the user, but not both. Further this boot does not allow progressive flexing of the boot or adjustment of the flex and canting of the boot.

[0008] It is critical that a skier be able to flex the boot in order to obtain desired performance from the skis. The ability of the skier to “flex” their knees forward from a normal substantially upright position “drives” the ski into a carved turn as well as to absorb bumps and differences in surface terrain and texture. This flexure allows the ski to change from one side edge to the opposing side edge in order to “carve” or turn the ski. This type of flexing to create a carved turn is created by the skier rotating about the skier's ankles. At the same time, the skier must maintain control of the skis. Also, the flexing motion is critical in allowing the skier to absorb the impact of bumps and differences in surface terrain and texture while maintaining control.

[0009] A primary consideration in the recent design of ski boots has been to maximize and optimize this forward flex. However, this was typically done at the expense of the lateral stability that affects control. Not only must a skier be able to flex forward in the boot to enhance skiing performance, but the boot must provide lateral and torsional stability for the skier to maintain the control necessary for skiing performance. Thus, a critical feature of ski boots is the ability of the upper portion of the ski boot to flex forward while the overall lateral stiffness of the ski boot is maintained.

[0010] This critical feature of the ski boot to flex requires a relative stiffness in the boot. The pressure from the skier is considerable during the flexing motion. Thus, a tendency in prior ski boots is to allow the boot to be easily flexed which detracts from the performance of the boot and the control of the skier. Further, the flexibility of prior ski boots has been temperature dependent. The flexing characteristics of the prior boots would vary greatly from the room temperature environment in which the boots were initially demonstrated to the changing temperatures in the skiing environment. The mechanical elements of the prior ski boots which provided the flexing of the ski boot, typically a metallic or plastic spring element, have physical characteristics which change with temperature differences.

[0011] A further important design feature is the control of the flex and springback, that is the return of the boot from the forward flexing to the normal skiing position. Different skiers have different needs as far as the amount of flex and the degree of resistance of the flex. Therefore, the design of a performance ski boot incorporates the ability to adjust the degree of the flex of the ski boot as well as the consistent progressive resistance of the flex, particularly as relating to the consistency of the flex through a wide range of temperatures. Additionally, the flex needs to be progressive in order to complete the turn, that is the resistance level of the flex may increase during the flex of the upper portion of the boot relative to the lower portion of the boot.

[0012] A number of prior ski boot designs attempted to provide a ski boot that would allow the skier to flex the boot forward relative to the ski about a fixed pivot point in order to improve ski performance. These designs typically include ski boots having a lower shell with an upper cuff that is movable about a fixed axis, usually a rivet, on the lower shell. A number of different devices have been used to allow the controlled movement of the upper cuff relative to the lower shell to provide the desired flexing of the ski boot. These devices include spring-loaded systems, flexion devices, elastomer bushings, and others.

[0013] Spring-loaded boots were initially used with coil springs incorporated into the mounting between the upper cuff and lower shell of the boot to provide a resistive force for the rotating motion. These boots fail to provide appropriate dampening and are affected by changes in the temperature.

[0014] Examples of the prior flexion devices in prior designs of flexible boots are disclosed in U.S. Pat. No. 4,777,742, issued to Petrini et al. and U.S. Pat. No. 5,329,707, issued to Chaige et al., which describe flexion element boots. These boots use a front flexible element to provide flexibility and resistance in the pivoting action about a rigid axis between the upper cuff and the lower shell.

[0015] There have been several attempts to incorporate an elastomer into the ski boot in order to provide flexibility of the upper portion of the ski boot relative to the lower portion. These types of designs are typified by the boots disclosed in U.S. Pat. No. 4,611,415, issued to Tonel and in German Patent 1481166. These boots use a loose elastomer disc to provide dampening between the upper cuff and the lower shell. This allowed some movement of the upper cuff relative to the lower shell but the critical feature of the lateral stability of the boot was lost. Additionally, there was no capability to regulate the degree of flex or to provide any control of the flex movement.

[0016] Another problem with the prior elastomer-type flexing elements is that these elements “bulge” during compression. This creates pressure against the ankle of the skier during the flexing causing discomfort to the skier.

[0017] Another critical problem with the prior ski designs is that the skier's forward movement in flexing the upper portion of the boot is caused by the skier moving about the ankle joints, while the boots typically pivot about a fixed axis. The ankle joint, however, from an anatomical point of view, does not pivot about a fixed axis, or even about a purely laterally movable axis. The ankle joint partially rotates about an axis which moves in a sliding lateral arcuate motion relative to the foot. Thus, the prior ski boots artificially constrain the motion of the ankle in the pivotal movement of the cuff relative to the shell. This often creates discomfort and inhibits the proper flexing movement of the skier. It can also lead to possible injury to the ankle joint itself. Also, the ski boots utilizing elastomers were unable to provide significant lateral stability. This lateral stability is critical in skiing performance.

[0018] Even the elastomer flexing units disclosed in the above-identified parent application, U.S. patent application Ser. No. 09/170,84, incorporated herein by reference, require a two-point pivoting mechanism. These units require additional mechanical elements and increase the complexity of the ski boot.

[0019] Another problem with the prior designs is the possibility for serious knee injuries. Most ski boot designs have increased the height of the cuff to improve the control and stability in the use of the boot. Unfortunately, this increased height has increased the stress on the knee joint, not only in the forward direction but as the skier returns back to the normal upright position after flexing forward. This increased pressure, whether under the torque of stopping or slowing the speed of the skier or when the skier moves or falls to the rear, can cause injury, especially and most commonly to the anterior cruciate ligaments of the skier. The rearward movement of the skier against the stiffness of the boot pushing forward against the calf of the skier's leg can be devastating to the anterior cruciate ligaments if the skier does not have time to recover. This is even more devastating if a torquing or twisting motion occurs. This is particularly significant due to the stiffness of the boots when flexing or moving rearward to the normal upright position. The prior ski boot designs are concerned with the forward flexing of the ski boot, not with absorption, and resistance to the rearward movement of the skier. The reduction of injuries of this type have not been addressed by the prior ski boots.

[0020] Yet another problems with existing ski boots are the fastening mechanisms. Existing boots utilize buckle mechanism to tighten and secure the boot onto the user. It is awkward to tighten these buckle mechanisms, particularly on the ski slope. Additionally, it is difficult to adjust the buckles for proper fit. Even when the buckles are properly adjusted, the foot of the user often swells during use of the boot creating “hot spots” on the user's foot or other discomfort.

[0021] The present invention provides a ski boot design which addresses these problems and others with an improved ski boot that provides controlled flex action of the upper cuff and lower shell.

SUMMARY OF THE INVENTION

[0022] The present invention solves these and other problems by providing a boot for skiing, snowboarding, and other activities. The boot of the present invention provides high performance with improved comfort. The boot includes a stiff frame for support and for translating energy directly to the ski, snowboard or other equipment, a conformable cuff and shell for improved fitting and comfort and a walkaway inner boot for comfort. The present invention provides a boot formed of composite materials rather than a single material of prior boots. This enables the use of materials having specific properties for particular functions.

[0023] In a preferred embodiment, the boot of the present invention includes a stiff upper frame formed of high strength, lightweight materials. An open-face conformable cuff is mounted to the upper frame for engaging the user. The cuff, in a preferred embodiment, is able to be adjusted relative to the upper frame and is able to rock slightly relative to the upper frame.

[0024] The boot also includes a stiff lower frame formed of materials similar to the upper frame. The upper frame is pivotally attached to the lower frame by a controlled flex unit. In the preferred embodiment, the controlled flex unit includes an oval plug or stub that is surrounded by an elastomer ring. In this embodiment, the elastomer ring includes a differing thickness to provide progressive flexing in the forward direction and a stiffer flexing in the rearward direction to minimize injuries. The unique controlled flex unit enables the upper framer to move forward, rearward, upward and downward relative to the lower frame without sacrificing lateral and torsional stability of the boot. The stiffness and performance of the controlled flex unit can be varied by substituting different elastomers and/or by adjusting the canting of the post.

[0025] In a preferred embodiment, a bumper is also provided to connect the lower frame and upper frame near the rear of the boot. This provides shock absorption as well as additional control between the lower frame and upper frame.

[0026] The boot also includes a shell attached to the lower frame. The shell includes a substantially open face and is formed of a soft conformable material to engage the inner boot and the user. The inner boot is a soft, durable, insulated walkaway boot. In use, the user may wear the inner boot until the use of the entire boot is necessary. The user simply inserts their foot and inner boot into the open face of the cuff and shell and tighten the buckles. The stiff upper and lower frames provide the requisite support for the activity. The controlled flex unit provides the transfer of power from the user and upper frame to the lower frame and the equipment.

[0027] In another preferred embodiment, the boot is similar to the above boot, except that a closed shell is used instead of the above shell having a substantially open face. The closed shell may be of a soft conformable material to engage the inner boot and/or foot of the user.

[0028] In additional preferred embodiments, the boot includes the capability to adjust sizes. The lower frame may be shortened by trimming the toe portion and using a shorter heel pad. The toe portion of the shell may also be trimmed. This enables a single boot to be adjusted for several sizes.

[0029] In another preferred embodiment, the lower frame and shell include an adjustable canting mechanism. This enables the boot to be adjusted to differing biomechanics.

[0030] In another preferred embodiment, a unique lacing system replaces the use of buckles. This unique lacing system provides ease of securing and adjusting the boot to the user's foot as well providing uniform strain over the user's foot.

[0031] These and other features of the boot of the present invention are evident from the ensuing drawings and detailed description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 is a perspective view of a preferred embodiment of the boot of the present invention.

[0033]FIG. 2 is an exploded assembly view of the boot of the embodiment of FIG. 1.

[0034]FIG. 3 is a partial cutaway view of the bumper connection between the upper frame and lower frame of the embodiment of FIG. 1.

[0035]FIG. 4 is a partial cutaway view of the embodiment of FIG. 1 showing the lower surface of the boot.

[0036]FIG. 5 is an exploded assembly view of the controlled flex unit of the boot of the embodiment of FIG. 1.

[0037]FIG. 6 is a reverse view of the controlled flex unit of FIG. 5.

[0038]FIG. 7 is an assembled view of the controlled flex unit of FIG. 5.

[0039]FIG. 8 is a cutaway view of FIG. 7.

[0040]FIG. 9 is a view of the inner boot.

[0041]FIG. 10 is an exploded assembly view of the lower frame and shell of the boot of the embodiment of FIG. 1.

[0042]FIG. 11 is a perspective view of the lower frame of another preferred embodiment.

[0043]FIG. 12 is a lower perspective view of the assembled lower frame and shell of the embodiment of FIG. 11.

[0044]FIG. 13 is a side view of the adjusted sizes of the embodiment of FIG. 11.

[0045]FIG. 14 is an exploded assembly view of another preferred embodiment of the boot showing the adjustable canting mechanism.

[0046]FIG. 15 is a front perspective assembly view of the embodiment of FIG. 14.

[0047]FIG. 16 is a perspective view of another embodiment of a boot securing system.

[0048]FIG. 17 is a view of another embodiment of the boot securing system of FIG. 16.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0049] A preferred embodiment of the present invention is illustrated in FIGS. 1-10. It is to be expressly understood that the descriptive embodiments are provided herein for explanatory purposes only and are not meant to unduly limit the claimed inventions. The preferred embodiment of the present invention includes a ski boot for use in alpine, Nordic, telemarking and other types of skiing, snowboarding, inline skating or other types of activities. The boot is referred to herein as a “ski boot” for descriptive purposes but is not meant to be limited for use with this activity. This invention is a continuation-in-part of U.S. application Ser. Nos. 09/170,344 and of 09/535,670, both of which are incorporated herein by reference.

[0050] The boot of the preferred embodiments of the present invention includes a very stiff power frame with controlled flex for transferring force from the user to the ski, a cuff and shell that conforms comfortably to the skier's body, and a comfortable liner that can, in some preferred embodiments be used to walk in. The boot provides the user with high performance as well as comfort.

[0051] Power Frame

[0052] The boot 10 of the descriptive embodiment, as shown in FIG. 1 includes an upper frame 20 that provides structural support for the lower leg of the skier, a cuff 30 that wraps around the lower leg of the skier, a lower frame 40 that forms the structural base under the foot and around the ankle of the skier, a shell that covers only the foot and is mostly open; and an inner boot 300. It is to be expressly understood that this preferred embodiment is intended for descriptive purposes only. Other types of boots, included one similar to this descriptive embodiment but having a substantially closed lower shell are also within the scope of the present invention.

[0053] The upper frame 20, shown in FIGS. 1-3 is formed of a high strength, relatively lightweight, stiff plastic material, such as glass filled polyamide. In the preferred embodiment, the upper frame includes a glass-filled material, such as nylon with about forty percent (40%) glass or Isoplast (produced by Dow Chemical) with about forty percent (40%) glass. It is to be expressly understood that other suitable materials may be used as well having very stiff characteristics. For example, carbon fiber, polycarbonate or other stiff materials may be used as well. The upper frame includes two opposing apertures 22, 24 for connection with the controlled flex units 200 and lower frame 40, as discussed below. Soft rubber bumper 28 is mounted within an interior recess of upper frame 20 and connects to a projection on lower frame 40, as shown in FIG. 3, and discussed in greater detail below. The upper frame also includes a substantially open face 26, as can be seen in FIG. 2.

[0054] Cuff 30 is attached to the upper portion of the upper frame 20. In the preferred embodiment, the cuff is adjustable by height and/or by angle relative to the upper frame. This can be accomplished by using tracks or other adjustable securing devices. The cuff may also rock to accommodate different shin angles and movement during use. Cuff 30, in the preferred embodiment, is formed of a lightweight material, such as a flexible urethane or other flexible materials. In the present invention, the cuff 30 is softer than the upper frame, preferably in the range of about forty-seventy five shore A durometer. This allows the cuff to conform about the shape of the user's calves and shins. One or more buckles 38 are attached to the cuff 30 to secure the boot 10 about the liner 200 and the skier. The opposing buckle is attached to the upper frame 20.

[0055] The lower frame 40 is also formed from a stiff material similar to the upper frame, such as a glass-filled material, such as nylon with about forty percent (40%) glass or Isoplast (produced by Dow Chemical) with about forty percent (40%) glass. It is to be expressly understood that other suitable materials may be used as well having very stiff characteristics. For example, carbon fiber, polycarbonate or other stiff materials may be used as well. The lower frame 40 includes an upper portion 42 for attachment to the upper frame 20 through the use, in the preferred embodiment, of controlled flex units 200, 260, as discussed in detail below. Lower frame 40 includes toe portion 44 extending from the front of the lower frame and a recessed heel portion 46 near the rear of the lower frame. The lower surface of the lower frame includes a first set of two holes (not shown) near the front of the lower frame and a second set of holes in the recessed heel portion 44 of the lower frame.

[0056] Shell 50, shown in FIG. 2, is formed from a soft urethane or other flexible material, similar to the materials used in forming the cuff 30. The shell 50 includes a substantially open upper face to facilitate entry into the boot with buckles 54 to cause the shell to conform about the inner boot and foot of the user. The shell includes an extended toe portion 56 and an open rear portion 58. In the preferred embodiment, the shell 50 includes a substantially oval shaped apertures 60, 62 for receiving the controlled flex units 200, discussed below. The lower surface of the shell 50, in the preferred embodiment, will normally have a tread pattern for gripping. Also, in the preferred embodiment, the lower surface of the shell includes two sets of holes 64, 66 near the front portion of the shell and a third set of holes near the heel portion of the shell.

[0057] Replaceable heel pad 80 is formed from hard rubber or other material that provides adequate wear while affording some gripping capability in the preferred embodiment attaches to the lower frame 40. In the preferred embodiment, heel pad 80 includes an extended flange 82 that inserts between the shell 50 and lower frame 40 to minimize debris buildup. Holes 84, 86 extend through the heel pad 80.

[0058] Controlled Flex Unit

[0059] The controlled flex unit of the preferred embodiment is disclosed in FIGS. 2 and 5-8. It is to be expressly understood that the descriptive embodiment is disclosed for explanatory purposes only and is not meant to limit the scope of the claimed inventive concept. The controlled flex unit 200, shown in FIG. 2, on ski boot 10, in the preferred embodiment includes an identical unit (not shown) on the opposing side of the boot 10.

[0060] The flex unit 200 is inserted through the inner portion of the upper frame 20. It is to be expressly understood that other mounting techniques could be used as well, such as mounting the flex unit on the outer side of the cuff. Flex unit 200 includes cap 202, shown in FIGS. 5 and 6, having a first side surface 204, a second reduced diameter side surface 206 and stub 208 mounted centrally in the inner surface 210 of cap 202. In one embodiment, stub 208 includes ridged surface 212 on it's outer surface. An aperture 214 extends through the center of cap 202 and stub 208. Bracket 216 includes a side surface 220 having a series of spaced notches 224 and teeth 226. Post 228, shaped in an oval design as discussed above, includes an indentation 230 dimensioned to snugly receive stub 208 of cap 202, as shown in FIG. 8. Ridges 232 are formed in the inner surface of indentation 230 to mate with the ridged surface 212 of the stub 208. The ridged surfaces 212, 232 allow up and down adjustment between the post and the stub for canting or lateral adjustment between the shell and the corresponding flex assembly. This feature is not found in any other boot assembly and provides greater adjustment to enhance the performance of the boot and the skier.

[0061] Elastomer ring 236 includes an outer dimension substantially equal to the inner dimensions of bracket 216 and an inner dimension substantially equal to the outer dimension of post 228. Elastomer ring 236, in the preferred embodiment, includes materials that have the characteristics of being temperature independent in the range of temperatures normally found in skiing environments. Examples of these materials, for use in the preferred embodiment, are disclosed in U.S. Pat. Nos. 5,611,155 and 5,740,620, both of which are incorporated by reference herein. In the preferred embodiment, the elastomer ring 236 is injection molded directly between the post 228 and the bracket 216. This ensures that the elastomer ring 236 “sticks” to the post 228 and the bracket 216. The elastomer ring 236 thus “flows” from the stresses during the flexing motion of the boot as discussed in greater detail below.

[0062] It is to be expressly understood that the elastomer ring 236 can also be formed as a separate piece as well as injection molded. The separate elastomer ring 236 can thus be inserted during assembly between the post 228 and bracket 216.

[0063] In the preferred embodiment, shown in FIG. 6, the elastomer ring 236 is asymmetrically shaped, that is, portions on one side of the ring 236 are thinner than other portions of the ring 236, as discussed in greater detail below. It is to be expressly understood that other shapes and dimensions of the elastomer ring can be used as well. Elastomer ring 236 is fitted between post 228 and bracket 216.

[0064] In another preferred embodiment, elastomer ring 236 is substantially oval in shape in lieu of the asymmetrical shape discussed above. This provides ease in the fabrication of the elastomer ring.

[0065] Aperture 234 extends through the center of post 228. Aperture 240 is formed in the upper frame 20 of the ski boot. The aperture 240 includes a series of spaced teeth 242 and notches 244 to mate with the notches 224 and teeth 226 of the bracket 216. An inner surface 246 in aperture 240 forms a hard stop against the inner surface of bracket 216.

[0066] As shown in FIGS. 7-10, the components of flex unit 200 are assembled as follows. Bracket 216 is inserted into aperture 234 so that the notches 224 and teeth 226 of the bracket 216 engages into the notches 244 and teeth 242 of the aperture 240. Elastomer ring 236 mounts within bracket 216 and around post 228. The indentation 230 of post 228 engages over the stub 208. Two screws (not shown) are inserted through aperture 214 and engage in threads in aperture 234 of stub 208.

[0067] Once the unit is fully assembled and the screw is tightened securely, the post 228 is fully engaged against the stub 208 on the lower frame. The side surfaces of the post 228 are also engaged against the elastomer ring 236 which is supported by the bracket 216 attached to the upper cuff. Thus, forces from the skier against the upper frame are transmitted by the bracket 216 and thicker portions of elastomer ring 236 against the post 228 and the lower frame.

[0068] As the forces are increased between the elastomer ring 236 and the post 228, the elastomer ring flows from the pressure. The elastomer ring 236 flows from the shear stresses in the material, as opposed to compression of other elastomer materials. While the forces on the elastomer ring 236 are discussed as primarily due to shear stresses, it is to be understood that compressive and tensile stresses are present as well during the use of the boot in skiing. The flow of the elastomer ring is due to the combination of these stresses, particularly to the shear stresses, as opposed to the compressive stresses in the prior art ski boot elastomers. This flow of material results in the elongation of the elastomer material in some areas and displaces in other areas instead of the bulging of the elastomer material in the prior art ski boots. As the forces are decreased, the material of the elastomer ring moves back into it's original shape and position. As the elastomer ring 236 returns back to it's original position, the opposing sides of the elastomer ring engage the post 228 to dampen the movement of the upper shell and the skier. This dampening of the upper shell minimizes the shock of a hard stop or twisting due to falling of the skier.

[0069] Additionally, the dampening of the upper shell relative to the lower shell also absorb shock forces that occur during skiing, providing a smoother skiing experience.

[0070] The asymmetrical shape of the elastomer ring 236 provides increased resistance in the forward movement of the upper shell while providing a lesser resistance in the rearward movement. This is critical as the rearward movement of the skier from a normal position should only be a few degrees, preferably 2-5 degrees. In the preferred embodiment, the boot allows the skier to move rearward about one inch (at the skier's knee area or about one-fourth inch at the typical boot top) to allow time for the skier to recover to minimize damage to the skier's leg, and particularly to the anterior cruciate ligament of the skier.

[0071] Also, in the preferred embodiment, the post 228 is canted about twelve degrees relative to the longitudinal axis of the bracket. The canting of the post 228 provides a softer flex in the forward movement of the upper cuff while providing a stiffer flex in the rearward movement of the upper cuff.

[0072] The amount of resistance can be easily altered by material choice for the elastomer ring as well as varying the thickness of the elastomer ring 236. The elastomer ring 236 against post 228 provides the only connection between the upper cuff and lower shell. This reduces wear and tear on the connection mechanism.

[0073] This unique controlled flex unit enables the upper frame to move forward, rearward, upward and downward relative to the lower frame without sacrificing the lateral and torsional stability of the ski boot. The ankle of the skier is not forced to pivot about an axis in an artificial manner. The ankle moves in a sliding-type movement that is natural and not constrained. Additionally, the controlled flex unit provides progressive resistance and/or shock absorption to enhance the performance of the ski. A further benefit is the shock absorption in the rearward movement of the upper cuff past the normal position to minimize injury in a hard stop or fall.

[0074] Additional benefits include the consistent performance of the boot regardless of the environmental temperature. Also, the characteristics of the flex unit can be changed by replacing the elastomeric rings. Further, the complexity of the ski boot is reduced by this novel unit, thus reducing the weight and cost of the boot.

[0075] It is to be expressly understood that other embodiments and variations of the preferred embodiment are considered to be within the scope of the claimed inventions. In particular, the embodiments disclosed in U.S. patent application Ser. No. 09/535,670 filed on Mar. 22, 2000, and Ser. No. 09/170,334, filed on Oct. 13, 1998, commonly assigned to the present assignee are hereby incorporated herein by reference.

[0076] Inner Boot

[0077] The inner boot 300, shown in FIGS. 2 and 9, is in the preferred embodiment, a walk-away inner lining with a supportive sole. In this preferred embodiment, the inner boot 300 is formed of a softer material, such as a compression molded EVA foam layer for precise fit. All or part of the inner layer may include a heat moldable material to provide for a customer fit. A support stiffner extends down the medial side of the inner boot to the outsole to transfer energy and to provide increased support. A breathable window can be added to reduce moisture buildup. The outer layer of the inner boot is formed of a waterproof material. This provides protection during use, since the power frame is essentially open. The inner boot also includes an overlap tongue having a smooth inner lining for comfort that also facilitates entry into the boot, maintains the foot dry and transfer energy to the cuff more efficiently by eliminating movement of layers.

[0078] The sole of the inner boot includes the Multiple Contour Sole, developed by Comfort Products Ltd. of Aspen, Colorado and disclosed in U.S. Pat. Nos. 5,575,089; 5,572,805; 4,316,335; and 4,316,332, all incorporated herein by reference. The upper part 310 of the Multiple Contour Sole includes a soft urethane foam. The outersole 320 includes hard blown rubber with tread molded into it. The outersole of the inner boot also includes small studs and/or rubber to grip on snow and ice. It is to be expressly understood that other types of inner boots can be used with the composite boot of the present invention as well.

[0079] Assembly

[0080] The boot 10 is assembled by attaching cuff 30 to the upper portion of the upper frame 20 by using tracks or other adjustable attachment mechanisms to enable the cuff to be adjustable by height or angle. However, it is to be expressly understood that the cuff may also be permanently fixed, such as for racing or other desired performance use. Preferably, the cuff is able to rock to accommodate differing shin sizes and movement during use. Elastomer bumper (or other resilient material) 28 is located in the pocket in the upper frame slightly overlapping lower frame. A hole (not shown) in the bumper engages onto a bumper post on the lower frame. As the upper frame flexes relative to the lower frame, the bumper post moves within the bumper pocket under the constraints of the bumper 28. The bumper 28 absorbs not only shock during skiing, and shock from sudden stopping, it also performs in the manner of the asymmetric elastomer ring discussed above in allowing the slight rearward movement of the skier's leg during a hard stop or slowing or fall to reduce the occurrence of damage to the anterior cruciate ligament of the skier.

[0081] The shell 50 is attached to the lower frame 40, as shown in FIG. 10, by simply sliding the lower part of the lower frame 40 into the rear portion 58 of the shell until the toe portion 42 of the lower frame engages in the extended toe portion 56 of the shell. The shell 50 is secured to the lower frame by screws 70, 72 inserted through holes 64, 66 in the front portion of the shell 50 that threadingly (self-tapping or other types of screws) engage in the holes in the front portion of the lower frame 40. Heel pad 80 is attached by inserting the flange 82 between an overlap formed between the shell and the heel recess 44 of the lower frame. The upper portion of the heel pad 80 engages in the heel recess 44. Screws 74 are inserted through the holes 84, 86 of the heel pad and engage in the holes in the heel recess 44 of the lower frame. Additional screws may attach through the mid sole of the shell and lower frame for additional securement.

[0082] The upper frame is pivotally mounted to the lower frame by engaging the apertures 22, 24 over the posts 238 on the lower frame. The flex units 200, 250 is then mounted onto the posts 238, as discussed above to secure the upper frame to the lower frame while allowing controlled flexing of the upper frame (and cuff) relative to the lower frame and ski.

[0083] In the preferred embodiment discussed herein, the ski boot is formed of composite materials that fulfill unique features, as opposed to the boots made from a single material previously. The upper frame and lower frame are formed of a tough, lightweight material, such as glass filled nylon or other materials, to provide rigid stability to the boot. The shell and cuff are formed of a softer material, as discussed above, for comfort and to conform to the user. The elastomeric flex unit can be formed of a polymeric material that has the appropriate flexing and temperature resistant properties. The inner boot 300 can be formed of a lightweight, insulating material for comfort and to allow the user to walk away in just the inner boot.

[0084] Use

[0085] The user simply puts the inner boots 300 on for walking. Once the user is at the appropriate venue, the user can easily insert the inner boots in the open faces of the cuffs and shells and secure the buckles. The buckles are then tightened until the cuff and shell conform securely to the inner boots. This operation is then reversed when the user is finished with their activity. The user is much more comfortable in the inner boots as well as safer from slipping and falling.

[0086] Alternative Embodiments

[0087] An alternative embodiment of the present invention is illustrated in FIGS. 11-14. This embodiment enables several sizes to be accommodated from a single boot structure. In this embodiment, shown in FIG. 11, lower frame 40 includes two sets of screw holes 120, 122 in the lower surface. Also, toe portion 44 includes a marker line. Shell 50 includes two matching sets of screw holes, 124, 126, as shown in FIG. 12. In use, as shown in FIG. 18, for larger sizes the lower frame 40 and shell 50 are assembled as discussed above. For smaller sizes, the toe portion 44 of lower frame 40 is cut at the marker line. Also, toe portion 56 of the shell 50 is also trimmed accordingly. The shell and lower frame are then assembled together. Since the shell will slide further back onto the lower frame due to the shorter toe portions, a shorter heel pad 80 is used to accommodate the shorter length. Screws are inserted through the second set of screw holes to secure the lower frame and shell together. Thus, several sizes of boots can be assembled from a single set of components.

[0088] Another alternative embodiment is disclosed in FIGS. 14-15. The lower frame 40 includes a rear canting adjuster 66 extending downward from heel portion 46. The lower surface of the lower frame is substantially curved and includes a first portion 70, a second portion 72 extending angled from the first portion 70, a third portion 74 extending substantially parallel to the first portion 70 and a fourth portion 76 extending downward to and substantially parallel to the third portion 76.

[0089] An intermediate member 80 can be inserted as well to provide support to the shell or can be integrated into the base of the lower frame. The shell 50 includes a heel portion 102 having an upright member 104, a mid-portion 106 and a toe portion 108. The upper surface of the lower frame is curved to mate with the lower surface of the lower frame. The mid-portion 106 includes a bracket member 110 that mates with the lateral adjustment bracket 66 of the lower frame 40. The mid-portion also includes a plurality of slots 114 for reducing the weight of the ski boot.

[0090] The components of the ski boot, discussed above, are assembled together to form a composite boot. Adjustment screw 130 (not shown) is inserted to engage the lateral adjustment bracket 66. Movement of the adjustment screw 130 causes the lower frame to pivot relative to the base due to the interaction of the screw 130 with the lateral adjustment bracket 66 and the threaded hole 132 of the base and due to the curved surfaces of the lower frame, the shell and the base. This pivoting movement provides a canting adjustment to accommodate the differing biomechanics of different skiers.

[0091] Lacing System

[0092] In a preferred embodiment, the present invention provides a boot that includes a unique fastening mechanism. It is to be expressly understood that while the descriptive embodiment discusses the fastening mechanism for use on a ski boot, that this fastening mechanism has utility for other types of boots and shoes for many other activities as well.

[0093] A preferred embodiment of the unique fastening mechanism is shown in FIG. 16. Fastening mechanism 400 includes lace 410. In the preferred embodiment, lace 410 can be braided cable formed of metallic cable with a plastic sheathing, high strength plastic, fabric or other types of materials. In the preferred embodiment, lace 410 is braided and/or sheathed to minimize abrasion against the boot.

[0094] The boot 450, which can be a ski boot or other type of boot or shoe, in the preferred embodiment, includes an open face 452 on lower shell 454, and an upper cuff 456 pivotally mounted to lower shell 454. This structure is by way of example only, and is not meant to limit the present invention to this structure. In the preferred embodiment, boot 450 includes a series of guides 420 along the open face 452 on lower shell 454. These guides 420 can be reinforced gussets, tubes, other reinforced mechanisms or merely slots in the lower shell 454.

[0095] Guides 424, 426 are incorporated through the shell 454 at opposing sides of the upper end of open face 452. Plastic housings 428, 430 extend on the exterior of the upper cuff 456 from apertures 432, 434 on the upper cuff 456 extending to the guides 424, 426, respectively. The plastic housings 428, 430 terminate at ratchet mechanism 440.

[0096] Lace 410 is inserted through the plastic housings 428, 430, through apertures 432, 434, through guides 424, 426 and laced through guides 420. The terminal ends of lace 410 are secured in ratchet mechanism 440. Ratchet mechanism 440 includes an internal reel (not shown). It is to be understood that other mechanisms can be used as well under the present invention to tighten the lace.

[0097] In use, the user merely rotates the ratchet mechanism in one direction to uniformly tighten the lace 410. As the lace tightens, the lower shell conforms about the user's foot and/or inner boot. The uniform tightening of the lace 410 creates a uniform strain on the user's foot, thus minimizing any stress points. The lace can be easily adjusted, either by continuing to rotate in the same direction to tighten, or in the opposing direction to loosen the lace.

[0098] In the preferred embodiment, the ratchet mechanism includes a “dial” 442 that is pushed or pulled to actuate the ratchet for use, and pulled or pushed in the opposing direction to lock the ratchet in place.

[0099] In another embodiment of the present invention shown in FIG. 17, the same type of mechanism is utilized, except the boot includes a tongue 460. The tongue 460 includes internal tubes for routing lace 410 through the tongue.

[0100] Summary

[0101] The present invention provides a boot for skiing and other activities that provides a stiff frame for transferring power to the boot sole; a controlled flex unit that enables progressive and controlled flexing of the boot to transfer this force; a cuff and shell that conform comfortable to the user's body and an inner boot that is comfortable and can be walked in separate from the boot. These and other features will be set forth in the adjunct claims. 

What is claimed is:
 1. A boot for sport activity, said boot comprising: a rigid upper frame; a substantially open front on said upper frame; a cuff affixed to said upper frame; said cuff formed from a conformable material; a rigid lower frame; a substantially open upper surface on said lower frame; a shell affixed to said lower frame; said shell formed from a conformable material; and an attachment unit for pivotally attaching said upper frame to said lower frame while maintaining the lateral stiffness of the upper frame relative to the lower frame.
 2. The boot of claim 1 wherein said attachment unit includes: an elastomer member constrained for elongation and displacement movement during movement of said upper frame relative to said lower frame.
 3. The boot of claim 1 wherein said attachment unit includes: a post attached to one of said upper frame and said lower frame; an aperture in the other of said upper frame and said lower shell surrounding said post; and an elastomer member mounted between said post and said aperture and constrained for elongation and displacement movement during movement of said upper frame relative to said lower shell.
 4. The boot of claim 3 wherein said attachment unit includes: an elastomer member having a shape and material choice to allow said elastomer member to displace under pressure from said post and said aperture in a substantially non-compressive manner due to elongation and shear stresses in said elastomer member.
 5. The boot of claim 3 wherein said elastomer member includes: an elastomer ring.
 6. The boot of claim 1 wherein said boot includes: a flexible inner boot.
 7. The boot of claim 1 wherein said boot includes: a flexible inner boot having a supportive sole.
 8. The boot of claim 1 wherein said boot includes: a flexible inner boot having an outer sole for walking on surfaces.
 9. The boot of claim 1 wherein said boot includes: a flexible inner boot having a heat moldable inner layer for custom fitting to a user's foot.
 10. The boot of claim 1 wherein said boot includes: a flexible inner boot having at least one section that transmits moisture.
 11. The boot of claim 1 wherein said lower frame includes: a toe portion; a section on said toe portion that can be trimmed to reduce the length of said lower frame; a toe portion on said shell; and a section on said toe portion that can be trimmed to reduce the length of said lower frame wherein said lower frame and said shell are assembled together for a boot of a first size and said toe portion on said lower frame and said toe portion on said shell are trimmed and assembled together for a boot of a second size.
 12. The boot of claim 11 wherein said boot further includes: a first heel pad for assembly onto said lower frame for said boot of said first size and a second heel pad for assembly onto said lower frame for said boot of said second size.
 13. The boot of claim 1 wherein said boot further includes: a lateral canting adjustment mechanism on said boot for adjusting the canting of said boot laterally.
 14. The boot of claim 13 wherein said lateral canting adjusting mechanism includes: a first bracket on the under surface of said lower frame; a second bracket on said shell mating with said first bracket; and a screw mechanism engaging said first bracket and said second bracket for adjusting the canting of said boot.
 15. The boot of claim 13 wherein said lateral canting adjusting mechanism includes: a convex surface on the lower surface of said lower frame; and a concave surface on the mating surface of said shell.
 16. The boot of claim 1 wherein said boot further includes: a resilient bumper between said upper frame and said cuff.
 17. A boot for sport activity, said boot comprising: a rigid upper frame; a substantially open front on said upper frame; a cuff affixed to said upper frame; said cuff formed from a conformable material; a rigid lower frame; a substantially open upper surface on said lower frame; a shell affixed to said lower frame; said shell formed from a conformable material; a flexible inner boot; and an attachment unit for pivotally attaching said upper frame to said lower frame while maintaining the lateral stiffness of the upper frame relative to the lower frame, wherein said attachment unit includes an elastomer member constrained for elongation and displacement movement during movement of said upper frame relative to said lower frame.
 18. The boot of claim 17 wherein said attachment unit includes: a post attached to one of said upper frame and said lower frame; an aperture in the other of said upper frame and said lower shell surrounding said post; and said elastomer member mounted between said post and said aperture and constrained for elongation and displacement movement during movement of said upper frame relative to said lower shell.
 19. The boot of claim 17 wherein said elastomer unit includes: an elastomer member having a shape and material choice to allow said elastomer member to displace under pressure from said post and said aperture in a substantially non-compressive manner due to elongation and shear stresses in said elastomer member.
 20. The boot of claim 17 wherein said elastomer m ember includes: an elastomer ring.
 21. The boot of claim 17 wherein said flexible inner boot includes: a supportive sole.
 22. The boot of claim 17 wherein said flexible inner boot includes: an outer sole for walking on surfaces.
 23. The boot of claim 17 wherein said flexible inner boot includes: a heat moldable inner layer for custom fitting to a user's foot.
 24. The boot of claim 1 wherein said flexible inner boot includes: at least one section that transmits moisture.
 25. The boot of claim 17 wherein said lower frame includes: a toe portion; a section on said toe portion that can be trimmed to reduce the length of said lower frame; a toe portion on said shell; and a section on said toe portion that can be trimmed to reduce the length of said lower frame wherein said lower frame and said shell are assembled together for a boot of a first size and said toe portion on said lower frame and said toe portion on said shell are trimmed and assembled together for a boot of a second size.
 26. The boot of claim 17 wherein said boot further includes: a first heel pad for assembly onto said lower frame for said boot of said first size and a second heel pad for assembly onto said lower frame for said boot of said second size.
 27. The boot of claim 17 wherein said boot further includes: a lateral canting adjustment mechanism on said boot for adjusting the canting of said boot laterally.
 28. The boot of claim 27 wherein said lateral canting adjusting mechanism includes: a first bracket on the under surface of said lower frame; a second bracket on said shell mating with said first bracket; and a screw mechanism engaging said first bracket and said second bracket for adjusting the canting of said boot.
 29. The boot of claim 27 wherein said lateral canting adjusting mechanism includes: a convex surface on the lower surface of said lower frame; and a concave surface on the mating surface of said shell.
 30. The boot of claim 17 wherein said boot further includes: a resilient bumper between said upper frame and said cuff.
 31. A boot for active use, said boot comprises: a lower portion; guides formed in an upper part of said lower portion; a tightening mechanism; and a lace extending through said guides and connected to said tightening mechanism. 